Section 1.6 System Overview; Module Power-Up; Module Operation - Spectrum Controls 1734 User Manual

1-6 Chapter 1: Module Overview
Indicator State
Flashing Red/Green
Section 1.6
System
Overview
User's Manual Pub. 0300266-02 Rev. B
Description
Communication faulted and received an identify comm fault request -
long protocol.
Also displayed during power-up.
The module communicates to the controller via a 1734 Control Net, Device Net,
or Ethernet adapter. The module receives 5 and 24 VDC power through the bus
interface.

1.6.1 Module Power-up

At power-up, the module performs a check of its internal circuits, memory, and
basic functions. If no faults are found during power-up diagnostics, the module
status LED is turned on.
After power-up checks are complete, the module waits for valid channel
configuration data. If an invalid configuration is detected, the module will
generate a PLC fault. Once a channel is properly configured and enabled, it
continuously converts the input data to a value within the range selected for that
channel.

1.6.2 Module Operation

The 1734sc-IF4U module provides four, independent, analog input channels.
Each channel includes four selectable filter settings, and can be configured for
voltage, thermocouple, current, resistance or RTD input types.
The 1734sc-IF4U module uses a 20-bit Sigma-Delta ADC (Analog-to-Digital
Converter) to achieve 18-bit resolution. (This may be limited to 16-bits resolution
by backplane communication.) Inputs to the ADC are first multiplexed through
analog switches, and then buffered by a precision, low offset and drift,
programmable gain amplifier. The ADC also provides the programmable current
source used in resistive measurements.
The 1734sc-IF4U plug-in module communicates over its isolated CAN Bus
interface through the module backplane. The 1734 network adapter then
communicates to the PLC controller.